Method of constructing horizontal cylindrical tanks



June 23, 1942. w, SANDBERG 2,287,197

METHOD OF CONSTRUCTING HORIZONTAL CYLINDRICAL TANKS Filed March 19, 19403 Sheets-Sheet 1 WILLIAM A. SANDBERG A TTORNE Y June 23, 1%42. w. A.SANDBERG 2,287,197

METHOD OF CONSTRUCTING HORIZONTAL CYLINDRICAL TANKS I Filed March 19,1940 3 Sheets-Sheet 2 WILLIAM A. SANDBERG INVENTOR A TTORNEY June 23,1942. w. A. SANDBERG 2,237,197

METHOD OF CQNSTRUCTING HORIZONTAL CYLINDRICAL TANKS Filed Mafch 19, 19403 SheetsSheet 3 WILLIAM A. SAN DB ERG INVENTOR A r TQRNE Y Patented June23, 1942 METHOD OF CONSTRUCTING HORIZONTAL CYLINDRICAL TANKS William A.Sandber Los Angel'es, Calif., assignor to Lacy Manufacturing Company,

Los

Angeles, Calif., a corporation of California Application March 19, 1940,Serial No. 324,837

(Cl. 29-1482) s 3 Claims.

The invention relates to methods for constructing large cylindricaltanks in a horizontal position.

Tanks of this form, for the storage of light liquids or of compressedgases, have now attained great dimensions, as for example a diameter ofthirty-two feet and a length of over two hundred feet, and the demand isfor even larger tanks. Because of their size, which renders itimpossible to move them anyv great distance, these containers must beconstructed in the field, in the open airgand the methods conventionallyused in the shop for the assembling of smaller cylinders either failcompletely or become'unduly ccstly when applied under field conditions.

Tanks of this type are customarily-made up of a plurality of ringsjoined end to end, the longitudinal seams being staggered around thecircumference and the heads being hemispherical or otherwise outwardlycurved. They may be constructed with all theseams riveted, or with thelongitudinal seams riveted and the roundabout seams welded, or with allthe seams weld- The improvements making up the present invent'ioncomprise:

(a) The assembling of the tank from completerings assembled and at leastbolted up ina vertical position on the-ground, stayed againstdeformation and thereafter lifted into the horizontal position;

(b) A novel method for staying the rings'to prevent their deformation orcollapse while being handled and assembled;

(c) A novel method and means for supporting the tank while underconstruction and for setting it accurately on its permanent foundations.

As the terms vertical" and horizontal are likely to be confusing whenapplied to rings of which the diameter may be four or more times the-length,it is premised that either term is applied herein solely to the'cylindrical axis of the tank onto the ring rather than to themaadvantages set forth in the accompanying drawings andthe followingdescription thereof, in

which:

Fig. 1 is an elevation, on a minute scale, of a. completed tank on itspermanent foundations;

Fig.'2 is a plan view, on the same scale, showing the location on thejack foundations;

Fig. 3 is a fragmentary sectional view showing the location of the jacksas regards the circumference of the tank;

Fig. 4 is a diagram showingthe manner of connecting the battery of jackswith the source of hydraulic fluid;

Fig. 5 is a sketch showing a single ring in the position in which it isconstructed;

Fig. 6 is an end view of a ring illustrating the method of staying therings against deformation;

Fig '7 is a detail of a means for securing the ends of the stay rodstothe ring, and

Fig. 8 is an elevation of a ring in position .on the jacks. and anotherring approaching that position. v

Referring first to Fig. 1, the completed tank indicated generally at l0consists of a plurality of rings ll-ll and the heads l2l2. The tank isprovided with brackets |3l3 resting on expansion rollers l4l4 which inturn rest on structural steel or other columns l5-l5 supported bypermanent concrete foundations |6l6. The tank is also provided withgirdersv 36-36 which in this embodiment are shown as located inside thetank, though they may be placed outside if preferred.

The first step in the construction of plurality of jack foundations|'I-l1 spaced approximately as shown in Figs. 2 and 3. That is to say,the longitudinal spacing is such that the centers of the blocks coincidewith the centers of length of'the rings; the blocks are arranged instraight lines parallel to and equally spaced from the axis of the tanklocation, and the lateral spacing. is such that the centre of theblockis intersected by a radius which may be say 20/30 from the yertical. v I

On each of the foundation blocks is placed a hydraulic jack [8 whichpreferably but not necessarily carries at its upper end a roller l9.

These rollers; if used, facilitate the welding op erationv by,permitting the tank to be rotated in the cradle formed bythe two linesof rollers.

The entire assembly of jacks is connected as shown in Fig. 4 to anysource of hydraulic fluid (preferably water) under pressure, as forexama tank by the method herein proposed is to .provide a riveted buttstraps. Fig. shows such a com- 35. These are all manually operatedvalves, as

for example globe valves or water cocks.

It is essential that all of the jacks be connected to a common sourceofsupply, and it is also most desirable that all of the valves abovedescribed be provided. The purpose in placing all the Jacks incommunication, as they will be with all the valves except bleeder valves35 open (their nor.- mal operating position) is to cause the jacks toexercise an equal lifting effect even though the surface against whichthe rollers bear is out of round and/or out of alignment longitudinally,or

- in case individual foundation blocks should sub-- side below theiroriginal level. This greatly reduces the cost of jack foundations asthey can be relatively light and shallow.

The four valves 28-3l have two uses. With all the jacks incommunication, a temporarily unbalanced load such as may be produced bya concentration of workers or machinery in one end of the shell maycause that end to subside below its normal level, correspondinglyraising the other end. In such event the shell may be leveled by closingone pair of valves, as for example 29 and 3|, leaving the correspondingpair open and feeding a small amount of hydraulic fluid, and againopening these valves after level has thus been restored. Similarly, theshell may be moved over a short distance laterally by closing one pairof valves, as for example 30 and 3! and feeding hydraulic fluid throughthe opposite pair.

The individual inlet and bleeder valves 34 and 35 are used to collapse asingle jack in order to pass it over an obstruction. For example, inrotating the tank, a butt strap or rivet head may engage a jack roller,and in such case a high 1'0- tating force is required to cause theroller to ride over the obstruction by displacing fluid into theremainder of the jacks. This application of force is avoided by closingvalve 34 of this individual jack and opening bleeder valve 315,permitting the pleted ring H with the stay rods in place.

when the ring proper is completed, it must he stayed to preventdeformation, as the ratio of ring diameter to sheet thickness is sogreatzthat- I the rings have no intrinsic stifiness whatever.

Heretofore stays in compression-i. e., timber or steel braces-have beenused for similar purposes, but the weight and cost are excessive, and Ihave substituted braces in tension with a highly material economy and anincreased ease of handling. Diametric stay rods even if arranged ofequal angles do not answer the purpose, as while such stays maintainopposite points of the circumference equally distant, they do notnecessarily maintain the circular form; in fact if the ring. besuspended at two points it assumes a pear-shaped outline which cannot bemated to the part of the shell already assembled. I have thereforedevised the method of staying shown in Fig.6.

In this structure, 31 is a centrally'located disc of steel plate and38-38 are radial tie rods welded or otherwise fastened to the plate asat 39. These rods may be threaded at their outer ends, passed throughthe clips (Rig. 7), and tightened by.means of nuts 4|. The clips may bewelded or'bolted to the-ring or, if preferred, the rod ends themselvesmay be welded lightly thereto. The radial angles should be equal and anydesired number of stay rods may be used, in-fact in very large rings itmay be desirable to use two discs spaced one-third or one-half thelength of the ring and a set of stay rods projected from each. Thismethod of staying provides a ring which is stiif without being rigid; sothat it may be lifted and swung into place without deforming whilehaving enough local flexibility to permit it to be mated readily withthe ring in place to which it is'to be joined. s

The next step in construction is to assemble the rings on the cradleformed by the jacks. Assembly may be started at any point along thelength of the tank, usually at the end farthest from the ring assembling.platform. A ring Ila. is picked up by a crane, using the slingindicated at .42 in Fig. 8, is set in place on one pair of Jacks (theinlet valves on all being closed),

1 is lifted to the desired level for construction by found convenient,the jacks are set at such height that the tank constructed on them isclear of these foundations. If the main and service lines are laid andprovided with valves, it is not necessary to put the jacks themselvesinto place until they are required, when they can be set in pairs I asrings are ready to be placed on them, thus keeping the working spacesubstantially clear.

The above described supporting and operating elements having beenprovided, the first step in the actual construction of the tank is toset up and stay the rings ll of which it is composed,

these rings being built meet a time as they are assembled to form thecomplete shell. This operation is performed on a reasonably levelsurface at or near ground level, the curved sheets being placedvertically to form the ring and the ends joined in the preferred manner,ordinarily by manipulating the valves of the'two jacks supporting it.and-finally is guyed as at 43-43 in Fig. 8 to prevent it fromoverturning. The next ring lib is then picked up and swung into place onthe next pair of jacks and fastened to the first ring. by the usual boltclips 44, and this operation is repeated until the length of the shellis complete, admitting fluid to each pair of jacks as soon as the ringis in place over them. Only the first ring is guyed and the guys mayberemoved as'soon as two or three rings are bolted together.

If it is desired to locate the girders inside the tank, as shown in thisillustration, it is preferable to-place them in the appropriate ringswhile the latter are being constructed on the When the cylindricalportion of the shellhas been assembled and bolted up, the heads areplaced and the tank is finished by any preferred riveting or weldingoperations. Ordinarilythe longitudinal seams will have been finishedinadvance and only the roundabout seams will remain to be formed. Duringthis operation, and particularly when welding, it is desirable to rotatethe tank on the cradle formed by the jack rollers, so as to bring theseams being worked on into the most convenient position. This may bedone by means of an encircling cable and a winch. To avoid tipping ofthe jacks while rolling the tank on them, it is desirable to connectthem in pairs by beams such asindicated at 45 in Fig. 3.

The tank is now tested for tightness, usnsuy with air pressure, afterwhich a part of the testing pressure is relieved and any externalgirders are placed and welded to the shell. The

tion, and assembling said rings end to end; resting each ring asassembled on two points of support; hydraulically applying a liftingeffect to said supporting points as said rings are rested thereon andthereby bringing the adjacent ends of said rings into abutting position;joining said abutting ends to form a continuous cylinder and maintainingsaid lifting effects in hydraulic balance during said joining step toprovide uniform support for said cylinder and prevent distortionthereof; attaching, heads to the ends of said cylinder to forms.substantially closed tank, and finally lowering said tank into itspermanent position by withdrawing said hydraulic effect.

tank is then shifted, laterally and longitudinally I, as may berequired, into its exact position over the permanent foundations, and isleveled; The

brackets 13 and expansion rollers M are then put into place and thebrackets fastened to the tank, or to the outer face of the girder,according to the location of the girder. Finally, the hydraulic pressureis removed from the jacks, which are withdrawn; the tank is deflated;and the stays and hub plates are removed through a manhole. The clips 40may be left in position 92' knocked oil as may be preferred, and thestays quired for the tank by joining the straight ends of arcuatelycurved sheets; staying-said rings to" prevent deformation when saidrings are lifted;

' lifting said rings to an axially horizontal posiand hubs'salvaged foruse in succeeding con- 2. A method of staying cylindrical tank sectionsagainst deformation while assembling said sections to form a cylinderwhich comprises: extending radial tension members from a common centerto substantially equally spaced points adjacent the inner wall of saidsection, and (attaching'the outer ends of said members to said wall insuch manner as to place all of said members in substantially equaltension.

3. In a method of constructing horizontal cylindrical tanks whichconsists substantially in joining the ends of preformed and stayedcylindrical rings while said rings are assembled in end abutment and inaxially horizontal position: the steps of. resting each said ring duringthe assembling operation on two points .ofsupport,

of hydraulically applying a lifting effect to said completed.

WILLIAM A. SANDBERG.

